Apparatus for clearing mine fields



June 1948- A. R. WILLIAMS 12,442,390

NIN

"Filed March 10, 1944 2 Sheets-Sheet l J6 I i awe/WM 1411130103. Williams June 1, 1948. A. R. WILLIAMS 2,442,390

APPARATUS FOR CLEANING MINE FIELDS Filed March 10, 1944 2 Sheets-Sheet 2 Patentecl June 1, 1948 UNHH'ED STATES PATENT ()FFIEE APPARATUS FOR CLEARING MINE FIELDS Allison R. Williams, Yazoo City, Miss.

Application March 10, 1944, Serial No. 525,962

(Granted under the act of March 3, 1883, as

1 Claim.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to mine field clearing devices and particularly to such devices carried by the track plates or tread plates of a standard military tank or other heavy vehicle of the track laying type. The invention also contemplates the use of heavy kinetic energy absorbing masses constructed in accordance with the teachings of my application Serial Number 519,142, filed the 21st day of January, 1944, which has matured into Patent No. 2,425,018.

In that application, I have disclosed the use of impact elements capable of traversing a mined area and exploding any mines planted therein by impact and sustained pressure. According to the principles disclosed in that application, it is proposed to reduce substantially the forces applied to the supporting and conveying structure for the impact elements by so designing those elements relatively to area exposed to the blast of an exploding mine and the mass of the exploder'ele- F was where F=mean retarding force required to bring the element to rest in distance S,

Ws=exploder weight,

S=travel of exploder before coming to rest,

K=a constant for a reasonable range of the variables A and W5, A=effectiv area exposed to blast.

It is apparent from this empirical formula that the retarding force necessary to bring the exploder to rest varies directly as the area of the exploder subjected to the mine and inversely as the Weight of the exploder and the length of its travel before coming to rest. Consequently, the

value of F may be controlled to obtain a desired value for the velocity imparted to the exploder by suitable proportioning of the quantities in the Tests have indicated that the above formula,

amended April 30, 1928; 370 O. G. 757) constant K is not the same for every area and every weight, but increases somewhat as the area increases and as the weight decreases.

The object of the present invention is to provide exploders which may be attached directly to the track blocks or tread plates of a military tank so that the tank may itself act as a mine field clearer. It is also proposed to so design and proportion these exploders-that they may absorb a substantial portion of the kinetic energy from the blast of an exploding mine, only a small fraction of the energy liberated from the blast being imparted to the exploder as kinetic energy, so that only a moderate force is applied to the tread and its conveying means. In this way, use may be made of a standard vehicle requiring only minor changes, which could be accomplished in the field.

By the use of exploders attached directly to the tread plates, as by welding, substantially the only changes required in the standard structure willbe the use of plates with stronger supporting pins of the tread, of the bogie wheels which have a thicker rim and an extra plate of metal in the bottom of the tank body so as to protect the occupants from the nearness of the blast and the added pressure which will be applied to' the tank body as a result of the use of exploders carried by the tread.

The invention will be more fully understood from a reading of the following specification in connection with the accompanying drawings in which:

Figure 1 is a side view of a portion of a'so- 'called medium tank showing a section of the tread with mine exploders attached to it;

Figure 2 is a front view of one form of exploder shoe embodying my invention as it appears attached to the tread plate of a tank;

Figure 3 is a side view of the shoe of Figure 2;

Figure 4 is a bottom plan view of the exploder shoe shown in Figure 2;

Figure 5 is a bottom plan 'view of a companion exploder shoe adapted for use in conjunction with that of Figures 2 and 3;

Figure 6 is a front view of the exploder shoe shown in Figure 5; and

Figure '7 is a developed view of the pattern made by the exploder shoe tread as it passes over a mine field, indicating how the exploder shoe ends cover the area so as to strike all areas within which anti-tank mines of known size could be planted.

Referring to Figure 1 of the drawings, this figure shows enough of the tank to illustrate the principle of the invention, other parts being broken away. In this figure; reference character I i designates the tank body having, in accordance with usual practice, an endless tread on each lateral side, the portion of one only of these treads being shown in the drawing. The tread as shown is made up of tread plates or blocks l connected together bylinks H! running about bogie Wheels I 2 supported on axles I3. The treads are, of course, driven by an internal combustion engine disposed Within the tank body and are subjectto control in any conventional manner through main drive sprockets. Since the driving mechanism and its control is not a part of the invention, further description will be unnecessary.

The tread plates I5 carry at each 'endtwo pins 2| (Fig. 3), and the pins of adjacent plates are joined by the links M and clamping devices of known construction permitting removal and replacement of any tread plates at will. In accordance with the present invention, each of the tread plates has welded thereto a heavy mass exploder element carrying either two or'three mine exploding projecti'onsor-shoes. As-shown in-Figure 2 the tread Iplate has welded thereto as indi cated at 22 an exploder I 6 carrying two projections 13 having exposed ends of small cross sectidn tapering and enlarging into the body of the mass which at its base has a configuration-and dimensions similar to'the-fa'ce of the tread plates P5. The base of theexploder extends laterally beyond the tread'plat-es'in such-away as to form shoulders 23 to protect the-tread-pi-ns-2l from the bla'stof an expl'oding mine. The streamlining of this 'base is such that there :areno exposed corners or projections-to present a vulnerable section to the'blas't' of an exploding mine. gThe mass of the -ex'plode'r with itsiprojection' is;of--oourse, designed according to the equation indicated above so 'as to reduce to asafe'value the amount of force which isappliedt'o the tread-and its supporting =means.

In' orde'rto provide apattern of "contact areas between the-ground-and theexploder feet or foot prints, the explod-er-elemen-ts !6 having two proje'ctions are alter-riated'with similar element's H havingthree projections. The explo'der lThasa central projection 1-8 similar-to the project-ions 18' carried by'the explode-r 16. However, adiacent-to the two ends of each 'expl'oder H --are-projections l9 thinner than the projections 18,18

and a'lso'stre'amlined and designedtopresentthe minimumof "exposed suriace to the blast of an exploding minabeneath'the end of the proiBction. The ground contacting face of the exploder l -I is indicated -inFigure o anda side View of-the same constructions-ppears in liigure 6.

The developedpat-tern or foot print produced on the -grouhd as the --tank "travels-along is indicated in Figure -'7, where it will beseen that not-only is there a symmetry ofthe points of supportior the tread and its superimposed weight, but a lso that the "projections +8, [8 and 19 are so positioned relative to each other as 'toexplo'de any anti-tank mine whiohmay be buried in the area oithe tank tread. The dotted "circles "24 -represen t mines "of the minimum size likely to beiencountered.

Experience has shown that-few anti-tank mine?- which will be encountered will be capa-ble :oi exerting an upward energy of more than-60, 000 foot-permds. The explodersshown-in -Figures 2 to G-"m'ay be d'esigned accordingto'the'above equation so as to reduce energy transmitted -to th'e tread and-its support to ---less than OlflG-tEhlEh of this-amount. V of that which-is imposeduponthetreadstructure by the weight-ofthe-tank -itselfas it travels along by the trigger 'wire 'or-othervrise.

This stress is not :greatly in excess 7 the explod'er.

iicie'nt pressure over any buried mine, whether the tenam be muddy, rocky or smooth to explode same. 'By causing a plurality of tanks to travel albng'i'n echelonan area can be covered effectively so as to clear it of buried mines. The arrangement is efiective even in the presence of barbed wire entanglements which may be erected around "the mine fieldor the use of booby traps or other impeding implements which may be used. The arrangement is particularly effective and orders er-decided improvement over prior art equipment providing-against the use of remotecontrol mines, that is mines which are detonated through the use of wires attached to'the minetrigger and then set some distance away. Remote controlled mines of thischaracter afford aserious menace todevices heretofore designed for mine field clear- -i-ng since it-islpossiblefor the mine'clearer to pass over the mine without exploding 'it and to go some distance ahead before setting off the mine Thus the body of the vehicle or tank pushing or-propelling the clearing device over the mine'field'may be immediately over the-mine when-the explosion occurs;

andthe tan-k-or vehiclegnot being built to be selfprotective against such explosion, will be disabled .--or destroyed with its-occupants.

Asindicated'inFigure 1, the projections 18, Hi and lfi wili-exert pressure-over the surface of the ground as the tank passes along and whenever these projections *passover a mine such as that designated fl'in Figure -1, themine will be ex .ploded' and-theexploding-force will be largely dis sipated as internal stress of the heavy mass of Therema-in-ing'portion of the con.- trollable energy from the exploding mine is transmitted through the tread plates "#5 to the bogie wheel 4 land-:astill furtherireduce'd amount to the otheriparts -ofthe conveying means.

Althoughin this description emphasis is placed upon the use-era :ta-nkas the mine field clearing vehicle, it is obvious that the tread modification may be applied 'to any type of vehicle. It will be clear from the above description that the tread plate with projections or feet may be replaced in the same manner that a broken tread plate is'replaced on any track-laying vehicle.

Also, while it is indicated that the exploders welded to the tread p]ates,'it is "obvious that it may be desirable in some instancesto form the exploders integral with the tread plates. The

-material of the exploders should be hard armor ploded by ltheprojections be deflected away .from

the tread a-pl-ate supports and its major .eiiect :7 exerted upon the projections themselves.

While a specific embodiment of the invention has been shown and been described, it will be understood that various alterations may be made without departure from the spirit of the invention as indicated by the appended claim.

Having thus described the invention, I claim:

Mine field clearing apparatus comprising a track-laying vehicle having an endless tread with tread plates, connecting pins extending laterally of the track from each of said tread plates, and a streamlined mine exploder mass of mine blast resistant material integral with each one of said tread plates, said mine exploder mass including a streamlined base portion provided with shoulders extending laterally of the track and over the respective tread plate connector pins thereby providing shielding means therefor, and a plurality of tapered streamlined mine exploding projections integral with said body portion, each of said projections extending to an exposed outer end of relatively small cross section in a groundengaging direction substantially at right angles to the plane of said one of said tread plates, said projections being relatively spaced at a. distance insufficient to accommodate an anti-tank land mine therebetween, each of said projections enlarging streamlined from said outer end thereof into said body portion to present the minimum of exposed surface to the blast of an exploding anti-tank land mine.

ALLISON R. WILLIAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 15 Number Name Date 7 891,954 Ross et a1 June 30, 1908 1,329,316 Wickersham Jan. 2'7, 1920 1,693,215 White Nov. 27, 1928 1,725,057 Carlsson Aug. 20, 1929 20 1,822,132 Davis Sept. 8, 1931 1,908,045 Olson May 9, 1933 2,146,101 Weber Feb. 7, 1939 2,168,053 Starr et a1. Aug. 1, 1939 

